Merge tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull misc vfs updates from Christian Brauner:
 "This contains the usual miscellaneous features, cleanups, and fixes
  for vfs and individual filesystems.

  Features:

   - Block mode changes on symlinks and rectify our broken semantics

   - Report file modifications via fsnotify() for splice

   - Allow specifying an explicit timeout for the "rootwait" kernel
     command line option. This allows to timeout and reboot instead of
     always waiting indefinitely for the root device to show up

   - Use synchronous fput for the close system call

  Cleanups:

   - Get rid of open-coded lockdep workarounds for async io submitters
     and replace it all with a single consolidated helper

   - Simplify epoll allocation helper

   - Convert simple_write_begin and simple_write_end to use a folio

   - Convert page_cache_pipe_buf_confirm() to use a folio

   - Simplify __range_close to avoid pointless locking

   - Disable per-cpu buffer head cache for isolated cpus

   - Port ecryptfs to kmap_local_page() api

   - Remove redundant initialization of pointer buf in pipe code

   - Unexport the d_genocide() function which is only used within core
     vfs

   - Replace printk(KERN_ERR) and WARN_ON() with WARN()

  Fixes:

   - Fix various kernel-doc issues

   - Fix refcount underflow for eventfds when used as EFD_SEMAPHORE

   - Fix a mainly theoretical issue in devpts

   - Check the return value of __getblk() in reiserfs

   - Fix a racy assert in i_readcount_dec

   - Fix integer conversion issues in various functions

   - Fix LSM security context handling during automounts that prevented
     NFS superblock sharing"

* tag 'v6.6-vfs.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (39 commits)
  cachefiles: use kiocb_{start,end}_write() helpers
  ovl: use kiocb_{start,end}_write() helpers
  aio: use kiocb_{start,end}_write() helpers
  io_uring: use kiocb_{start,end}_write() helpers
  fs: create kiocb_{start,end}_write() helpers
  fs: add kerneldoc to file_{start,end}_write() helpers
  io_uring: rename kiocb_end_write() local helper
  splice: Convert page_cache_pipe_buf_confirm() to use a folio
  libfs: Convert simple_write_begin and simple_write_end to use a folio
  fs/dcache: Replace printk and WARN_ON by WARN
  fs/pipe: remove redundant initialization of pointer buf
  fs: Fix kernel-doc warnings
  devpts: Fix kernel-doc warnings
  doc: idmappings: fix an error and rephrase a paragraph
  init: Add support for rootwait timeout parameter
  vfs: fix up the assert in i_readcount_dec
  fs: Fix one kernel-doc comment
  docs: filesystems: idmappings: clarify from where idmappings are taken
  fs/buffer.c: disable per-CPU buffer_head cache for isolated CPUs
  vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
  ...

1 files changed, 31 insertions, 4 deletions

diff --git a/fs/fs_context.c b/fs/fs_context.c
index 30d82d2979af..a0ad7a0c4680 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -162,6 +162,10 @@ EXPORT_SYMBOL(vfs_parse_fs_param);
 
 /**
  * vfs_parse_fs_string - Convenience function to just parse a string.
+ * @fc: Filesystem context.
+ * @key: Parameter name.
+ * @value: Default value.
+ * @v_size: Maximum number of bytes in the value.
  */
 int vfs_parse_fs_string(struct fs_context *fc, const char *key,
 			const char *value, size_t v_size)
@@ -189,7 +193,7 @@ EXPORT_SYMBOL(vfs_parse_fs_string);
 
 /**
  * generic_parse_monolithic - Parse key[=val][,key[=val]]* mount data
- * @ctx: The superblock configuration to fill in.
+ * @fc: The superblock configuration to fill in.
  * @data: The data to parse
  *
  * Parse a blob of data that's in key[=val][,key[=val]]* form.  This can be
@@ -315,10 +319,31 @@ struct fs_context *fs_context_for_reconfigure(struct dentry *dentry,
 }
 EXPORT_SYMBOL(fs_context_for_reconfigure);
 
+/**
+ * fs_context_for_submount: allocate a new fs_context for a submount
+ * @type: file_system_type of the new context
+ * @reference: reference dentry from which to copy relevant info
+ *
+ * Allocate a new fs_context suitable for a submount. This also ensures that
+ * the fc->security object is inherited from @reference (if needed).
+ */
 struct fs_context *fs_context_for_submount(struct file_system_type *type,
 					   struct dentry *reference)
 {
-	return alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT);
+	struct fs_context *fc;
+	int ret;
+
+	fc = alloc_fs_context(type, reference, 0, 0, FS_CONTEXT_FOR_SUBMOUNT);
+	if (IS_ERR(fc))
+		return fc;
+
+	ret = security_fs_context_submount(fc, reference->d_sb);
+	if (ret) {
+		put_fs_context(fc);
+		return ERR_PTR(ret);
+	}
+
+	return fc;
 }
 EXPORT_SYMBOL(fs_context_for_submount);
 
@@ -333,7 +358,7 @@ void fc_drop_locked(struct fs_context *fc)
 static void legacy_fs_context_free(struct fs_context *fc);
 
 /**
- * vfs_dup_fc_config: Duplicate a filesystem context.
+ * vfs_dup_fs_context - Duplicate a filesystem context.
  * @src_fc: The context to copy.
  */
 struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc)
@@ -379,7 +404,9 @@ EXPORT_SYMBOL(vfs_dup_fs_context);
 
 /**
  * logfc - Log a message to a filesystem context
- * @fc: The filesystem context to log to.
+ * @log: The filesystem context to log to, or NULL to use printk.
+ * @prefix: A string to prefix the output with, or NULL.
+ * @level: 'w' for a warning, 'e' for an error.  Anything else is a notice.
  * @fmt: The format of the buffer.
  */
 void logfc(struct fc_log *log, const char *prefix, char level, const char *fmt, ...)